In the field of business machines, there are areas of such machines which are arranged so as not to be accessible to the operator under certain operating conditions. One of the areas of such machines is in a higher voltage area so that the operator is protected from accidentally coming into contact with such higher voltage.
In the case of a socket or like receptacle for receiving a power source such as a plug or the like, it is known that a slidable member or shutter is provided to cover the socket or receptacle. In this regard, the plug cannot be inserted into the socket when such socket is covered and an effort must be made on the part of the operator to uncover the socket in order to insert the plug.
In the known arrangement, the structure has a disadvantage in that a power source plug cannot be inserted into a socket until the slidable member or shutter is moved and it may be difficult for the operator to move the shutter and also to insert the power source plug at the same time. Additionally, the slidable member or shutter protrudes in front of the socket to prevent insertion of the plug and if the socket is not entirely uncovered, the slidable member or shutter may be damaged by forcing the plug into the socket.
Representative documentation in the field of interlock devices includes U.S. Pat. No. 1,620,814, issued to B. E. Getchell on Mar. 15, 1927, which discloses an electric safety switch wherein a fuse box has a cover with an opening that is closed by a slide. The slide has a flange positioned between a switch handle and an edge of the cover so as to prevent the slide from being opened when the switch is closed.
U.S. Pat. No. 2,752,413, issued to A. H. Junkins on June 26, 1956, discloses an electrical interlock for coupling elements and is swingable from a closed to an open position. The interlock has an aperture for receiving one coupling element when the interlock is in the closed position.
U.S. Pat. No. 3,068,442, issued to J. T. Kubik et al. on Dec. 11, 1962, discloses a safety guard for wall sockets that includes a single control for covering one or both of the socket openings.
U.S. Pat. No. 3,147,056, issued to H. Mendelson on Sept. 1, 1964, discloses a protective interlock structure that includes a panel movable to cover an opening in a wall and which positions a cutout in the panel for receiving an electrical connector member, and movable to uncover the opening to prevent connection of two members.
U.S. Pat. No. 3,213,222, issued to J. D. Finley et al. on Oct. 19, 1965, discloses a switchgear shutter that includes a main shutter and an auxiliary shutter for closing openings in an upper row of openings and thereby preventing communication between front and rear compartments.
U.S. Pat. No. 3,660,798, issued to C. C. Marzec on May 2, 1972, discloses a mechanical interlock device having an L-shaped slide member movable between one position effective to prevent insertion of an electric plug into a socket and another position wherein it is ineffective to prevent such insertion.
And, U.S. Pat. No. 4,565,908, issued to F. Bould on Jan. 21, 1986, discloses drawout switchgear apparatus with retractable shutter mechanism, obstruction means retractably mounted for preventing movement of the shutter mechanism when the switchgear is removed from its cell, and trigger means for retracting the obstruction means when the switchgear is moved into the cell.